On Thursday, Kenney was over and we started poking around the machine seeing what the various knobs did. Found out that there is one pot on the audio amp that is, not surprisingly, the volume control. I haven’t been able to test the speakers yet, but turning the volume up makes a louder popping noise when the machine is turned on, so I figure that is a good sign. Once I figure out what wires are the line-in, I’ll give it a shot.
We then turned our attention to the dozen-plus knobs on the arcade monitor.
That picture only shows 9 of the knobs (6 white knobs on main board, a blue knob on the small daughter board to the right of the white knobs and two white knobs that are out of focus in the foreground), but you get the idea. We’ve got knobs for the following controls: Red Cutoff, Green Cutoff, Blue Cutoff, Green Drive, Red Drive (but no Blue Drive), Black Level, Vertical Hold, Horizontal Hold, Horizontal Centering, Vertical Damping, Vertical Size, Vertical Raster Position, Focus & Screen. Noticeably missing is Horizontal Size. We adjusted the monitor so the garbled characters that were coming up on boot-up at least looked like what we thought they should look like, but we couldn’t get the Horizontal Size adjusted, as there was no pot for this.
I then noticed a diagram of the controls on the side of the screen, amongst other “HIGH VOLTAGE” warnings:
So instead of a Horizontal Size knob, we had a Horizontal Width Coil. Great. How the fuck is that supposed to be adjusted. Hell, can it be adjusted? Neither of us were daring enough to stick a piece of metal with a handle down into it, so we went inside and played some NBA Jam.
The next day (Today/Friday) I started checking on-line, and found out there is a tool for this, basically a plastic hex wrench (so you won’t shock the shit out of yourself while adjusting it). Luckily you could adjust it with a regular hex wrench, you just need to turn off the machine to adjust it.
I went out to the garage, powered the machine on and marked where the image was on the screen with blue tape and turned off the machine. I twisted the small hex screw clockwise and turned the machine on. The image was now even narrower. I powered the machine off again, and turned the hux screw counterclockwise a bit. I repeated this a few times, but it seems the largest I could get the image was back to the original tape marks. I’m guessing either it’s too cold out (it is unseasonably cold in Minnesota right now), the image has too much black on it (I’ve noticed that the pixels on tube displays get wider when displaying white, and narrower when displaying black) or I need to get a cap kit and re-cap the monitor. Since I’m getting a good enough image, I’m not going to worry about that for now. I’ll cross that path down the road.
Today I also received my parts from Ultimarc, which means I can start working on getting the MAME PC up and running. The MAME PC was cobbled together from parts I had sitting around my basement. Unfortunately, I found out that I had one bad power supply in the basement, and it seems like either the motherboard or the CPU I picked out is fucked up too, as the XP install locked up at two separate points, and the machine won’t properly shut-down (sits at the Shutting Down… screen forever). Luckily I have another motherboard/CPU combo downstairs, as well as a working power supply, so I will need to see if I can get those to work together.
That will be my project while I wait for the Bob Roberts and Arcade Overlays orders to arrive.